@article{10_4171_ggd_171,
     author = {Hiroyasu Izeki and Takefumi Kondo and Shin Nayatani},
     title = {$N$-step energy of maps and the fixed-point property  of random groups},
     journal = {Groups, geometry, and dynamics},
     pages = {701--736},
     year = {2012},
     volume = {6},
     number = {4},
     doi = {10.4171/ggd/171},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/171/}
}